The present invention relates generally to storage systems and, more particularly, to remote copy between a primary storage system and a secondary storage system involving the use of performance data of the primary storage system in the secondary storage system.
Data storage system users are acutely interested in maintaining backup data in order to prevent loss of valuable data from failure in a storage unit which may result from occurrence of natural disasters, e.g., earthquake or storm. Currently, two operational modes are used by storage systems to copy the data to the backup or secondary sites: synchronous mode and asynchronous mode.
In synchronous mode, a write request from a host to the primary storage system completes only after write data have been copied to the secondary storage system and acknowledge thereof has been made. Accordingly, this mode guarantees no loss of data at the secondary storage system since the write data from the host is stored in the cache of the primary storage system until the acknowledgement has been received from the secondary storage system. However, the primary and secondary storage systems cannot be placed too far apart, e.g., over 100 miles, under this mode. Otherwise, the storage systems cannot efficiently execute write requests from the host.
In asynchronous mode, a write request from a host to the primary storage system completes upon storing write data only to the primary system. The write data is then copied to the secondary storage system. That is, the data write to the primary storage system is an independent process from the data copy to the secondary storage system. Accordingly, the primary and secondary storage systems may be placed far apart from each other, e.g., 100 miles or greater.
A storage system is typically optimized to achieve higher storage data access performance using recent access log data and performance data. For example, a dynamic tier manager changes a storage volume allocation in several different physical disks (e.g., SSD, SAS, and SATA) which have different performance characteristics. In the event of a disaster or system migration, the system at the primary site can be recovered using the backup data at the secondary site. However, it is difficult to achieve the same level of storage access performance at the secondary site because there are no performance log data at the secondary site. One example involves primary site and secondary site that are owned by different entities or enterprises such as, for example, a case involving a hybrid cloud environment. The user may find it difficult to keep the same level of performance after the user recovers the entire system using backup data, because the performance log data is not taken over from the primary storage system.
EP2056200A1 disclose method and system for the time-series performance history, in which a volume included in a storage device is managed as one time-series performance history at the time of data rearrangement or device change. However, it does not show how to take over the performance history data during remote copy. Moreover, a centralized monitoring system manages multiple storage systems. In the event of a disaster, all monitoring data will be lost.